Immunotherapy of mastitis.

The aim of this study was to examine an alternative, immunologically based treatment for mastitis. A microbead carrying specific anti-mastitis bacteria antibodies and an enhancer of phagocytosis, termed Y-complex, was tested in two experiments. In experiment 1, 21 cows were challenged with Streptococcus dysgalactiae and treated with Y-complex, Cobactan LC(®) or saline. Y-complex cleared the bacteria by day 4 and by day 10 only one cow was positive and remained positive up to day 28. No bacteria were isolated from any of the seven cows treated with Cobactan LC after day 4; however, in two out of the seven cows, the bacteria were re-isolated on day 24. On day 28, cows treated with placebo had still not cleared the bacteria. Experiment 2 was a field study in which cows, naturally infected with Escherichia coli, S. dysgalactiae or coagulase-negative staphylococci (CNS), were treated with Y-complex (32 cows), sulfadiazine+trimethoprim or procaine penicillin+streptomycin (BA) (8 cows), or a non-steroidal anti-inflammatory drug (NSAID) (19 cows). Y-complex was as effective as antibiotics, and superior to NSAID, in eliminating bacteria. Milk quantity and quality following infection and treatment were similar for all treatments, but significantly less milk was discarded from cows treated with Y-complex as compared to antibiotics. Y-complex was proven to be safe and effective, and may serve as a new approach for the treatment of mastitis.

Immunological complex for enhancement of innate immune response in passive vaccination.

Passive vaccination is used to treat a wide range of infections and cancer. However, this approach has some limitations. An immune complex termed Y-complex was developed to intensify the effect of the passive vaccine. The complex is composed of a microbead that carries specific antibodies and an inducer. It enables targeting of pathogen or abnormal cells, and stimulation of a desired response by innate immune cells, depending on the inducer. The production and efficacy of Y-complex as a passive immune prophylaxis is demonstrated in this study by its use in treating cow mastitis. In an in vitro assay, Y-complex inhibited propagation and induced phagocytosis of bacteria. In challenge experiments, cows were inoculated through the udder with Escherichia coli or Streptococcus dysgalactiae. Following treatment with Y-complex, no bacteria were isolated in the milk and N-acetyl-ß-D-glucosaminidase activity had returned to normal levels. Thus the Y-complex approach can be used as an effective treatment for mastitis. Due to its modularity, this approach may serve as a treatment for a variety of disease agents.